Very Huge Sized Cache of Duplicity

Solution 1:

According to the mailing list

you will have to manually exclude it ..

it holds your backup chains index files (table of contents of the backup repository). Caching them locally accelerates options like status and incremental backup and others. These operations need to know what is already backed up to work. If they are cached they do not need to be transferred and decrypted every time again and again.

.. ede

For the rest it seems to be a long standing bug.

On the Debian bug tracker, they recommend to

duplicity cleanup --extra-clean --force ....

Warning: The suggested --extra-clean option is dangerous and can bite you very hard. It makes backups unrestorable by usual means.